I designed the enemies with several mechanical goals and one big thematic goal:
The enemies aren't just made of cookie, they are cookies.
It was important to me to build the style and enemy behavior off of real-life cookie types. Instead of reskinning your classic zombie enemy to now be a "chocolate chip cookie zombie", I carefully chose each enemy's cookie to be a sort of pun of the cookie itself, and provide the ingredients necessary for the recipes we needed mechanically.
First I designed the enemy with its style and mechanical behavior, then I'd work closely with the pixel artist to create sprites that matched the design, and finally with those two elements the programmer would implement the enemy into the game.
Below are comparisons of each enemy to their cookies.